Substrate formed on carrier having retaining features and resultant electronic device

Abstract

A method for forming an electronic device on a flexible substrate conditions at least one surface of a carrier to form at least one retaining feature on the surface for retaining a flexible substrate. The flexible substrate is provided by deposition or lamination f one or more layers of substrate material onto the carrier. A portion of the substrate is processed to form the electronic device on the processed portion of the substrate. At least the processed portion of the substrate is released from the carrier to provide the flexible substrate having electronic device formed thereon. An electronic device is formed on a flexible substrate in accordance with the method.

The invention claimed is: 
     
       1. A method for forming electronic devices on a flexible substrate, the method comprising:
 conditioning a surface of a carrier to form at least one retaining feature on said surface of the carrier for adhering a flexible substrate on said surface of the carrier, the retaining feature formed in a shape of a continuous or segmented band surrounding a central region within the retaining feature; 
 forming the flexible substrate by deposition of one or more layers of flexible substrate material onto the surface of the carrier, the central region within the retaining feature, and onto the at least one retaining feature; 
 processing a portion of the deposited flexible substrate to form the electronic device over the central region within the retaining feature; and 
 releasing from the carrier the portion of the flexible substrate over the central region within the retaining feature to provide the flexible substrate having an electronic device formed thereon. 
 
     
     
       2. The method of  claim 1  wherein the carrier is glass. 
     
     
       3. The method of  claim 1  wherein the flexible substrate is metal. 
     
     
       4. The method of  claim 1 , wherein the step of conditioning the surface of the carrier comprises forming a continuous or segmented substantially rectangular retaining feature. 
     
     
       5. The method of  claim 1  wherein forming the flexible substrate comprises one or more of the following deposition processes: electroforming, evaporation, and plasma deposition. 
     
     
       6. The method of  claim 1 , wherein the step of releasing comprises cutting through the portion of the flexible substrate over the central region within the retaining feature and around the electronic device. 
     
     
       7. The method of  claim 1 , wherein the respective coefficient of thermal expansion values of the carrier and the flexible substrate differ from each other by more than 2 ppm/degree C, and wherein the step of releasing comprises cooling the substrate, cooling the carrier, or both, responsive to the respective coefficient of thermal expansion values. 
     
     
       8. The method of  claim 1 , further comprising reusing the carrier by repeating the steps of conditioning, forming, processing and releasing. 
     
     
       9. The method of  claim 1 , further comprising:
 forming a plurality of the retaining features, where the retaining features are arranged as a matrix of rows and columns on said surface of the carrier for retaining the flexible substrate thereon, and where each of the retaining features encloses a corresponding unit area on said surface of the carrier. 
 
     
     
       10. The method of  claim 9 , wherein the step of conditioning comprises treating said surface of the carrier by forming release features pattern-wise on said surface of the carrier, where the release features are configured to reduce adhesion in the areas between said surface of the carrier and the flexible substrate that contact the release features, and where each of the release features are formed within one of the corresponding unit areas enclosed by the retaining features. 
     
     
       11. The method of  claim 1  wherein the flexible substrate is plastic. 
     
     
       12. The method of  claim 1 , wherein at least one retaining feature comprises a lip formed on a backside of the carrier opposite said surface of the carrier for retaining the flexible substrate on the carrier. 
     
     
       13. The method of  claim 12  wherein the carrier is glass. 
     
     
       14. The method of  claim 1 , wherein at least one retaining feature comprises at least one groove formed in the carrier. 
     
     
       15. The method of  claim 1  wherein the flexible substrate is selected from the group including metals and plastics. 
     
     
       16. A method for forming thin film electronic devices on a flexible substrate, the method comprising:
 conditioning a surface of a carrier to form a regular pattern of release feature sections on said surface of the carrier for reducing adhesion of the carrier to the flexible substrate in the areas of said surface of the carrier that contact the release feature sections; 
 forming the flexible substrate by deposition of one or more layers of flexible substrate material onto the carrier and the release feature sections; 
 processing portions of the deposited flexible substrate that are over the release feature sections to form a thin film electronic device in each portion using deposition, patterning and etching; and 
 releasing at least the processed portions of the flexible substrate that are over the release feature sections from the carrier to provide a plurality of flexible substrates each having the thin film electronic device formed thereon. 
 
     
     
       17. A method for forming electronic devices on a flexible substrate, the method comprising:
 conditioning a surface of a carrier to form a plurality of retaining sections thereon, where the retaining sections are arranged as a matrix of rows and columns on said surface of the carrier for retaining the flexible substrate thereon, and where each of the of retaining sections comprises a corresponding unit area on said surface of the carrier; 
 conditioning a portion of said surface of the carrier to form a plurality of release sections thereon, where the release sections reduce adhesion in those areas between said surface of the carrier and the flexible substrate that contact the release sections, and where each of the release sections is formed within one of the corresponding unit areas of the retaining sections; 
 applying the flexible substrate by deposition of one or more layers of flexible substrate material onto the surface of the carrier, the retaining sections, and onto the release sections; 
 processing portions of the flexible substrate over the release sections using deposition, patterning and etching to form the electronic devices thereon; and 
 releasing the portions of the flexible substrate over the release sections from the carrier to provide the flexible substrate having electronic devices formed thereon. 
 
     
     
       18. The method of  claim 17  wherein the releasing comprises cutting the portion of the substrate with release features from a portion without release features. 
     
     
       19. The method of  claim 9 , wherein the flexible substrate includes a uniform thickness over the matrix of retaining features. 
     
     
       20. The method of  claim 19 , wherein each electronic device is formed within an inner boundary of the corresponding unit area on said surface of the carrier. 
     
     
       21. The method of  claim 20 , wherein the step of releasing comprises releasing and removing a plurality of electronic devices from the carrier by cutting through the flexible substrate within each said inner boundary to separate from the carrier a portion of the flexible substrate having one electronic device formed thereon. 
     
     
       22. The method of  claim 21 , wherein the electronic device comprises a thin-film transistor device.